Long-term objective: To find intervention therapies that can delay, prevent or reverse the development of type 1 diabetes (T1D). Specific Aims: 1) BHT-3021 Proinsulin DNA vaccine treatment of recent onset type 1 diabetes subjects Research Design: Preliminary data in animals has shown that using a similar proinsulin DNA vaccine can reverse diabetes in hyperglycemic mice. Pre-clinical studies in mice and non-human primates have found no toxicity for this therapy and have suggested a dosing scheme which could be effective in human subjects with T1D. An ongoing phase 1 study has confirmed the safety of this treatment and has suggested potential efficacy in type 1 diabetes subjects >3 months from diagnosis who still have C-peptide present. The current trial will test 2 doses, 1 and 3 mg, given weekly for 12 doses in a new onset patient population. It will use established measures to determine the effect on C-peptide, HbA1c, total insulin use and other safety parameters. Mechanistic studies to look at effects on insulin and other autoantibodies, T cells and other immune effects will be performed to better understand the potential mechanism of effect. 2) Renewal of TrialNet Center Research Design: The Barbara Davis Center has been at the forefront of defining populations at risk for T1D and other autoimmune diseases and in recruiting patients for the TrialNet Natural History study as well as other TrialNet studies. The BDC TrialNet Center has helped to develop two of the first protocols, TN02 (MMF and DZB in new onset T1D), and TN06 (Nutritional Intervention to Prevent [NIP] Diabetes). Our proposal for renewal outlines our past efforts, current approaches and future goals to not only maintain our current level of productivity, but to increase productivity over the next funding cycle.